Hydraulic motor operated formation tester



HYDRAULIC MOTOR OPERATED FORMATION TESTER Filed Jan. 29. 1954 G. H.RAMSEY July s, 1958 2 Shee ts-Sheet 1 F l G.

George H. Ramsey INVENTOR ATTORNEY July s, 1958 G. H. RAMSEY 2,842,210

' RMATION TESTER G e o r g e H R a m s e y N v E N T OR Unit HYDRAULICMOTOR OPERATED FORMATION TESTER Application January 29, 1954, Serial No.407,119

3 Claims. (Cl. 166-100) This invention concerns a novel form offormation tester for use in testing the fluids which may be produced ata given point along a Well bore. The apparatus of this invention is ofapplication in the exploration for oil and is. uniquely designed toprovide simple and efficient means for sampling fluids produced in abore hole at a given horizon or stratum ofthe earth.

In drilling a bore hole in the attempt to encounter oil deposits in theearth, it is conventional practice to employ a variety of tests todetermine whether or not oil may be produced from the bore hole,todetermine the nature of the oil, it any, and to determine from whichstratum or strata production should be attempted. The type of apparatusused to provide this type of information is generally called formationtesting apparatus. This term aptly identifies the principal objective ofthe apparatus: .to test the fluids existing at a particular stratum ofthe earth. For this purposea wide variety of formation testers areknown. A particularly attractive development of rather recent date hasbeen the development of inflatable packer type formation testers.Testers of this type have an elastic packer whichmay be inflated byfluid. pressures. so as to completely seal oflf a particular portion ofa bore hole. In one of its most desirable embodiments, a portion of theinflatable packer is provided with a permeable membrane, or alternativemeans, through which fluids maypass from strata ad- .jacent the sealedoff section of the borehole into channels and chambers provided in theapparatus to receive the sampled fluids. This type of packer provides aconvenient and effective manner of sealing off the drilling mud inthebore hole so that. a sample of Well fluids can be obtained from anydesired stratum of the bore hole.

One of the problems involved in obtaining fluid samples from a formationtester of this character is provision of a. suitable means forextractingfluid from the producing stratum. For example, it isoftenunsatisfactory to rely upon use of a vacuum pump at the surfaceof theearth to produce fluid from a stratum. The limitation inherent in use ofa vacuum pump is that an effective head of only about thirty feet ofwater may be applied on the producing stratum by this means. It

has been suggested to use a sample chamber which will be essentiallyevacuated when placed in fluid communication with the stratum to besampled. In this case evacuation of a sample of fluid from the formationwill be effectively. obtained; but itis apparent that the fluid capacityof the sample chamberis seriously limited. Consequently, it is one ofthe objects of this invention toprovide formation testing apparatus inwhich it is possible to obtain fluid flow from the formation to betested into a substantially empty drill .pipe. This technique providesan ample pressure differential which is applied at the producing stratumso as to ensure production and recovery of any fluid which maybepresent. Again, there is suflicient volume within the drill string(extending as it does to the surface of the earth) so that anyordinarily required volume of .fluid. sample may be withdrawn.

2,8412 10 Patented July. 8, 1958 Another problem connected with the useof inflatable packer type formation testers is provision of a suitablemeans. for inflating these packers. This problem becomes particularlydiflicult to solve when provision is made, as indicated, for use of anempty drill. string into which the produced fluid is to flow. In thiscase it is apparent that drilling mud cannot be circulated downwardlythrough the drill string to inflate the packer and that other means arerequired. It is one of the features of this invention, therefore, toemploy a hydraulic motor driven by the hydrostatic. pressure .ofdrilling mud .in the annulus of the bore hole about the drill string.This hydraulic motor may be directly coupled to a mudv pump which can beused toforce drilling .mud from the annulus of the bore hole'to inflatethe packer. A particular advantage of this arrangement is the simple andeffective operation made possible by effectivelyutilizing the pressuredifferential between drilling mud in the annulus .of the bore hole andthe empty drill string.

The formation tester of this invention, having the characteristicsgenerally indicated, may conveniently be designed to permit positivesequential operatingsteps. Thus, in a first step, inflation of thepacker of the formation testeris achieved'by operation-of the hydraulicmotor-mud pump combination. In a second step of the procedure thehydraulic motor and mud pump can be stopped and fluid can be producedthrough the inflated packer into the drill string. Finally, in a thirdstep of the process the packer'can be deflated so that theentireapparatus can be removed from thebore hole, thereby bringing to thesurface; the produced 'fluid contained 'within the drill string. It isone of the features of this invention to provide a sequential step-typevalve operation to carry out these essential steps in formationtesting.-

In' orderto fully illustrate the principles ofthis invention, referencewill bemade to the accompanying drawings, in which the preferred formofthe invention is schematically illustrated. In these drawings:

Figure 1 is a cross-sectional, elevational detail of'the formationtester illustrated in operative position as it would be in a bore hole;

Figures 2, 3, 4, and 5 are cross-sectional views of Figure 1 along theline IL-II illustrating the valve connections, and sequential valvepositions;

Figure 6 is afragmental, diagrammatic sketch of the valve operatinglatch;

Figure 7 illustrates a solenoid arrangement for actuating thevalve-operating ratchet mechanism of Figure 1; and

Figure 8 is a cross-sectioned schematic detailed view of valve 18 shownin Figure 1.

Referring to the drawings, the formation tester may be connected to adrill string 2 inorder to suspend the tester at any desired level in abore hole. The uppermost portion of the tester constitutes a valve 3operating within a valve body element 4 in which fluid' channels leadingto the valve are positioned. As illustrated, the valve body 4 may beconnected to the drill string 2 inthreaded relation. The valve 3' mayconstitute a plug valve held in the the, valve body by means of thecover plate 5. In order to permit sequential positioning of the valve, atorsion spring 6 is positioned about the valve stem so that in aninitial step of the operation the valve can effectively be Wound upagainst the force of the spring 6. A ratchet 7 which may be suitablyfixed to a support 8 carried by valve body 4 can be used to contactteeth out on the upper portion of the valve. As will bedescribed, theteeth are so.formed that each time the ratchet 7 is momentarily releasedthe valve will turn one quarter of a revolution.

In this manner the valve may be turned sequentially into any one of fourpositions so as to connect diflerent valve ports to the interior of thedrill pipe above the valve body 4.

Any suitable means may be used to operate the ratchet 7 in order to turnthe valve as desired. For example, a wire line 60 may be connected tothe ratchet 7 so that the valve can be turned each quarter turn whendesired. Again, for example, the ratchet may be controlled by a solenoid61 supported by arm 62 from support 8 as shown in Figure 7 so as tocontrol the different sequential valve positions. The solenoid may beoperated remotely from the surface of the earth through suitable leads63.

Suspended below the valve body 4 is a cylinder 9 within which issupported a centrifugal pump 10 and a hydraulic motor 11 which arediagrammatically illustrated by the rectangles in the drawing. Drillingmud maintained in the annulus of the bore hole has direct fluidcommunication with the inlet of the hydraulic motor through the port 12.The outlet of the hydraulic motor is connected to a conduit 13 whichextends upwardly so as to connect with fluid channel 14 in the valvebody 4. The hydraulic motor 11 may be directly coupled to thecentrifugal pump 10 through a shaft 15. The inlet of pump 10 is normallyin fluid connection with drilling mud in the annulus of the bore holethrough port 17. As will be described, a. valve 18 may be used to closethe port 17 when it is desired to discontinue operation of thecentrifugal pump. The outlet of the centrifugal pump is connected to aconduit 19 which leads to a second fluid channel 20 in the valve body 4.

The cylinder 9 carrying the centrifugal pump and fluid motor may befixed to the valve body 4 in any desired manner. For example, as shown,the cylinder 9 may be force-fitted over a reduced cross sectionalportion of valve body 4. An O-ring seal 23 or the like may be employedto ensure a fluid seal. Set screws 24 may be used to lock these elementsin position. If desired, keys 25 may extend along the cylinder 9 throughthe casing of the centrifugal pump and the casing of the hydraulic motorso as to maintain these elements in the proper rotational register. j

Suspended from the bottom of the cylinder 9 is a suitable form ofinflatable formation tester packer identified by number 30. As will beunderstood this invention may be employed with a wide variety ofinflatable packers. For example, one form of packer which may be used isthat described in U. S. Patent No. 2,600,173, issued to Ben W. Sewelland George H. Ramsey on June l0, 1952. This packer is fragmentallyillustrated in the lower portion of Figure l of these drawings. A shown,the inflatable packer may be connected to cylinder 9 by means of awirewrap 31. The necessary fluid connections to the packer may be madethrough a closure element 32 extending across the lower termination ofthe cylinder 9. One channel, indicated by numeral 33, may be cut throughthe closure element 32 so as to provide fluid access directly to theinterior of the packer so that fluid can be forced therethrough, forinflation of the packer. Channel 33 is connected to a conduit 34 whichin turn leads to a channel 35 cut in the valve body 4.

A second fluid connection to the formation tester packer 30 is madethrough the channel 37 which is connected to a formation fluid samplingpassage or tube 38 through which fluid produced during a formation testmay flow. A conduit'39 leads upwardly from the channel 37 for connectionwith a channel 40 in the valve body 4. The lower end of tube 38 extendsthrough the wall 70 of the packer and connects with a packet 71 which isfilled with a filling material as more fully described in theaforementioned Sewell et al. patent. l

Since the elements of the formation tester packer 30 are not a portionof this invention, no further description will be made of the formationtester. As indicated, it is only necessary to provide a fluid conduitsuch as conduit 34 through which drilling mud can be introduced toinflate the formation tester and also to provide a conduit 39 which canbe connected to the portion of the formation tester through whichproduced fluid can flow.

The operation of the apparatus described can be understood by referenceto Figures 2, 3, 4, and 5, which illustrate the fluid passages which areopened at different rotational positions of the valve 3. When theapparatus is to be lowered into a bore hole in order to carry out aformation test, the valve opening 45 will be in a first positionillustrated in Figure 2. In this position, the valve will be closed sothat fluid can neither flow into nor out of the drill string 2.Consequently, the packer of the formation tester will remain deflatedand neither the hydraulic motor nor the centrifugal pump will be inoperation.

When the formation tester has been lowered to the position in the borehole at which it is desirel to conduct a formation test, ratchet 7 istriggered so as to permit a quarter turn of the valve 3. The valve willthen be in the position particularly illustrated in Figure 3. In thisposition, the outlet of the motor, connected to conduit 13 and valveport 14 will be in fluid communication with the interior of the drillstring 2. Consequently, drilling mud can flow from the annulus of thebore hole through port 12 so as to operate the hydraulic motor. Thedrilling mud will be exhausted from the motor through conduit 13, fluidchannel 14, valve port 45, and thence into the drill string above thevalve body 4. Operation of the hydraulic motor in this manner willsimultaneously activate the direct coupled centrifugal pump 10. Thiswill cause drilling mud to be forced by thepump from the annulus of thebore hole through inlet 17 and through v conduit 19 to the valve body.In this step of the operation a cutaway 46 in the valve body serves toconnect channels 20 and 35 in the valve body so that the drilling mudpumped through conduit 19 will be forced through conduit 34. Therebyoperation of the centrifugal pump 10 serves to force drilling mud intothe inflatable packer 30 so as to inflate this packer. The centrifugalpump may be so designed as to deliver suflicient pumping pressure tosuitably inflate the packer without exceeding the rupture limits of thepacker. Alternatively, the arrangement illustrated in Figure 1 may beused to stop operation of the pump when a suitable inflation pressurehas been obtained. Thus, as illustrated, a conduit 48 may be connectedto conduit 34 so as to lead to the valve arrangement 18. The valve 18may be controlled by a spring biased piston so that when a selectedpressure has built up in the packer 30, valve 18 will be closed. It maybe noted that operation of this valve is simple and positive as thehydrostatic pressure within packer 30 will sharply build up wheninflation has been completed.

A sectioned schematic view of a simple valve 18 is shown in Figure 8.The valve illustrated there includes a piston attached to the valve stemwhich is biased against fluid pressure within conduit 48 by virtue ofthe spring 81.

In the next step of the operation, ratchet 7 is again triggered so as topermit the valve 3 to make another quarter turn. In this position of thevalve illustrated in Figure 4, the valve port 45 will be connected withchannel 40 in the valve body so that conduit 39 leading to the formationtester will be in direct fluid communication with the drill pipe. Thisposition of the valve will serve to cut 05 flow of drilling mud throughthe hydraulic motor so that the motor and pump will be stopped in thisstep of the operation. Since the drill pipe will be completely devoid offluid except for the drilling mud which as passed to it by operation ofthe motor, there will be opportunity for fluid at very low formationpressures to flow into the drill pipe. The apparatus may be maintainedto permit this flow for any desired period of time so that a substantialquantity of fluid sample can be obtained in the drill pipe.

In the next step of the operation ratchet 7 is triggered so that thevalve port 45 will be brought in register with channel 35 connecting tothe interior of the inflatable packer as shown in Figure 5. Thereby thepacker may exhaust into the drill string so as to deflate the packer.Regardless of the quantity of the fluid which has been sampled andtrapped in the drill string, the hydrostatic pressure of the drillingmud in the bore hole acting on the packer will be sufiicient to fullydeflate the packer during this step of the operation.

Finally, as the last step of the procedure the valve may again berotated a quarter turn to the position shown in Figure 2 so that valveport 45 is no longer in fluid communication with any conduits of theapparatus. Consequently all fluid which has entered the drill stringwill remain trapped until the apparatus is brought to the surface of theearth and this fluid can be removed.

It is apparent that the invention described is subject to manyrefinements and modifications. As indicated, the apparatus isillustrated diagrammatically, so that in actual construction it wouldnot be necessary to employ the different conduits referred to. Thecentrifugal pump, the hydraulic motor, and the valve body, for example,can all be constructed in an integral assembly provided with suitablechannels to carry out the fluid flow described. Again, it must beappreciated that this invention can be used with any desired type offormation tester other than the formation tester particularly-described.

Illustrated in Figure 6 is one modification permitting substitution of aweight activated valve latch in place of the wire line operated valvelatch described. In Figure 6, for clarity, the teeth 51, 52, 53, and 54at the upper portion of the rotary valve are illustrated in linearposition. The latch 7 is positioned above the teeth and is pivoted atpoint 55. On each side of the pivot point, two extensions 56 and 57extend downwardly in order to contact the teeth 51 to 54. Extension 56is somewhat longer than extension 57 and the distance between extensions56 and 57 is less than the distance between each of the teeth 51 to 54.The latch 7 may be constructed so that the anvil 50 is at the center ofthe bore hole. A torque spring about the pivot of the latch may be usedso that extension 56 is normally urged against the teeth 51 to 54.Consequently when a wire line suspended weight is dropped on anvil 50,extension 56 will be lifted free of the valve teeth while extension 57is brought downwardly enough to contact these teeth. In particular,valve tooth 52 would bereleased, as illustrated, and extension 57 wouldcontact tooth 53. This prevents possibility for the valve turning morethan one quarter turn.

When the wire line weight is then removed from the anvil, extension 56will contact tooth 53 as the valve turns, to establish the desired 90rotation of the valve.

What is claimed is:

1. In a well formation tester including an inflatable elastic packer anda sample conduit extending through the wall thereof, the improvementwhich comprises a cylinder attachable at its upper end to the lower endof a string of well pipe and at its lower end to said packer, ahydraulic motor and a pump in coupled relation mounted within saidcylinder, a four-position valve mounted within said cylinder above saidmotor and pump and separating the interior of the well pipe from theinterior of the packer, said valve having a shut-position and threesequential port positions, the movable part of the valve being rotatablewithin the valve body and having a passageway communicating at one endwith the interior of the well pipe, three separate ports in the body ofsaid valve, the opposite end of said passageway being blocked by saidvalve body in a first said shut-position and registering sequentiallywith a first, second, and third of said three ports in the followingthree port-positions, the intakes of said motor and said pump extendingexteriorly of said cylinder, a first conduit connecting the exhaust ofsaid motor with said first port, a second conduit connecting said secondport with the end of said sample conduit within said packer, a thirdconduit connecting said third port and the interior of said packer, anadditional port in said valve, a fourth conduit connecting saidadditional port and the exhaust of said pump, and a bypass passagewaywithin said movable part operable to communicate between said additionalport and said third port when the valve is in its first port position.

2. A well formation tester which comprises: a cylinder having a closureat its lower end and attachable at its upper end to a string of wellpipe; an inflatable packer attached to the lower end of said cylinder; ahydraulic motorand a pump in coupled relation supported within saidcylinder; a four-way valve including a valve body and a rotatablymovable part supported within said cylinder above said motor and saidpump; said valve body separating said string of drill pipe from theinterior of said cylinder; the intakes of said pump and said motor eachextending through and terminating exteriorly of said cylinder; saidvalve having a shut-position and three sequential port positions; thethree port positions being designated by a first port, a second port,and a third port, respectively; a passageway in said movable partcommunicating at one end with the interior of said pipe string; theopposite end of the passageway being blocked by said valve body in saidshut-position and registering sequentially with said first, second, andthird ports in the remaining three valve positions; a first conduitconnecting the discharge of said motor with said first port; a sampleconduit penetrating the wall of said packer; a second conduit piercingsaid closure and connecting said second port with the sampling conduitwithin said packer; a third conduit piercing said closure and connectingsaid third port with the interior of said packer; an additional port insaid valve body; a fourth conduit connecting the exhaust of said motorwith said additional port; a by-pass within said movable part connectingsaid additional port and said third port when said passageway is inregistry with said first port, said movable part being operable fromwithin said well pipe.

3. In a Well formation tester including an inflatable elastic packermounted at the lower end of a string of well pipe, the improvement whichcomprises a fourposition valve having an off-position and threesequential port-positions; said valve separating the interior of thewell pipe above the valve from the interior of the packer; first,second, and third ports in the body of said valve correspondingrespectively to said three port-positions; the movable part of saidvalve operable from Within the well pipe and having a passagewaycommunicating at one end with the interior of said well pipe, theopposite end of said passageway being blocked by the body of said valvein said ofi-position and registering sequentially with said first,second, and third ports in the three following port-positions of thevalve; a hydraulic motor and a pump in coupled relation supported bysaid well pipe; a first conduit interconnecting the exhaust of saidmotor with said first valve port, the intake of said pump and the intakeof said hydraulic motor terminating exteriorly of said well pipe andsaid tester, a second conduit extending from the exterior of said packerthrough the wall of said packer to said second port, a third conduitinterconnecting the interior of said packer with said third valve port,an additional port in said valve body, a fourth conduit interconnectingsaid additional port with the exhaust of said pump, and a by-passpassageway in said movable part adapted to interconnect said additionalport and said third port when said central passageway is in registrywith said first port.

References Cited in the file of this patent UNITED STATES PATENTS

1. IN A WELL FORMATION TESTER INCLUDING AN INFLATABLE ELASTIC PACKER ANDA SAMPLE CONDUIT EXTENDING THROUGH THE WALL THEREOF, THE IMPROVEMENTWHICH COMPRISES A CYLINDER ATTACHABLE AT ITS UPPER END TO THE LOWER ENDOF A STRING OF WELL PIPE AND AT ITS LOWER END TO SAID PACKER, AHYDRAULIC MOTOR AND A PUMP IN COUPLED RELATION MOUNTED WITHIN SAIDCYLINDER, A FOUR-POSITION VALVE MOUNTED WITHIN SAID CYLINDER ABOVE SAIDMOTOR AND PUMP AND SEPARATING THE INTERIOR OF THE WELL PIPE FROM THEINTERIOR OF THE PACKER, SAID VALVE HAVING A SHUT-POSITION AND THREESEQUENTIAL PORT POSITIONS, THE MOVABLE PART OF THE VALVE BEING ROTATABLEWITHIN THE VALVE BODY AND HAVING A PASSAGEWAY COMMUNICATION AT ONE ENDWITH THE INTERIOR OF THE WELL PIPE, THREE SEPARATE PORTS IN THE BODY OFSAID VALVE, THE OPPOSITE END OF SAID PASSAGEWAY BEING BLOCKED BY SAIDVALVE BODY IN A FIRST SAID SHUT-POSITION AND REGISTERING SEQUENTIALLYWITH A FIRST, SECOND, AND THIRD OF SAID THREE PORTS IN THE FOLLOWINGTHREE PORT-POSITIONS, THE INTAKES OF SAID MOTOR AND SAID PUMP EXTENDINGEXTERIORLY OF SAID CYLINDER, A FIRST CONDUIT CONNECTING THE EXHAUST OFSAID MOTOR WITH SAID FIRST PORT, A SECOND CONDUIT CONNECTING SAID SECONDPORT WITH THE END OF SAID SAMPLE CONDUIT WITHIN SAID PACKER, A THIRDCONDUIT CONNECTING SAID THIRD PORT AND THE INTERIOR OF SAID PACKER, ANADDITIONAL PORT IN SAID VALVE, A FOURTH CONDUIT CONNECTING SAIDADDITIONAL PORT AND THE EXHAUST OF SAID PUMP, AND A BY-PASS PASSAGEWAYWITHIN SAID MOVABLE PART OPERABLE TO COMMUNICATE BETWEEN SAID ADDITIONALPORT AND SAID THIRD PORT WHEN THE VALVE IS IN ITS FIRST PORT POSITION.